Intelligent microfluidic device for multiplex detection and prompt warning of upper and lower respiratory tract infections

The increasing incidence and co-infection rates of multiple respiratory diseases have emphasized the necessity for efficient and reliable multiplex diagnostic methods for respiratory pathogens. This study aims to develop a multiplex diagnostic tool for monitoring and early warning of respiratory infections. A portable, centrifugal and highly integrated microfluidic device based on real-time recombinase-aided amplification (RAA) assays capable of specifically identifying 15 common respiratory pathogens was developed. Its point-of-care application was validated using simulated swabs and sputum spiked with 15 pathogens. A total of 427 collected samples were employed to assess its clinical performance, in parallel with traditional extraction kits and RT-qPCR/qPCR assays. Additionally, the feasibility of its connected monitoring and early warning platform was validated across 22 scenarios in 8 cities of mainland China. This device successfully facilitated sample-to-answer diagnostics by automating nucleic acid extraction, real-time RAA, fluorescence detection and wireless data transmission. Compared with conventional methods, this device has obvious advantages in the turnaround time (30 min for swabs and 60 min for sputum) and the detectable targets/types in a single test. The lowest detection limits of this device were 0.1 TCID50/mL for viral targets and 10 CFU/mL for bacterial or fungal targets. This newly developed device has good versatility in detecting various types of pathogens (viruses, bacteria, and fungi) in clinical samples, achieving an AUC above 0.99 for all targets and an accuracy of 99.30 % in the analysis of 345 swab and 82 sputum samples. Moreover, this device achieved seamless data interaction with the intelligent monitoring and early warning system across 22 scenarios, enabling the successful visualization of data statistics and early warning analyses for uploaded information. This device provides an intelligent, portable, rapid, and sensitive platform for early diagnosis of multiple pathogens, particularly in resource-limited settings.